ÐWe study implementation issues for spatial convolution filters and their Fourier alternative, with the aim to optimize the accuracy of filter output. We focus on Gaussian scale-space filters and show that there exists a trade-off scale that subdivides the available scale range into two subintervals of equal length. Below this trade-off scale Fourier filtering yields more accurate results than ...

Speech signal consists of events in time and frequency, and therefore its analysis with high-resolution time-frequency tools is often of importance. Analytic filter bank provides a simple, fast, and flexible method to construct time-frequency representations of signals. Its parameters can be easily adapted to different situations from uniform to any auditory frequency scale, or even to a focuse...

In previous work, we have successfully used an ideal joint sparseness assumption: W-Disjoint Orthogonality (WDO). This assumption, that the time-frequency representations of the sources have disjoint support, is satisfied in an approximate sense by many signals of practical interest, including speech. Here we discuss results derived from a stochastic model of speech signals that justify the WDO...

In this paper, we use mutual information to characterize the distributions of phonetic and speaker/channel information in a timefrequency space. The mutual information (MI) between the phonetic label and one feature, and the joint mutual information (JMI) between the phonetic label and two or three features are estimated . The Miller's bias formulas for entropy and mutual information estimates ...

The Hilbert transformation together with empirical mode decomposition (EMD) produces Hilbert spectrum (HS) which is a fine-resolution timefrequency (TF) representation of any nonlinear and non-stationary signal. A method of audio signal separation from stereo mixtures based on the spatial location of the sources is presented in this paper. The TF representation of the audio signal is obtained b...

In this paper, redundant bases for denoising are constructed completely in the frequency-domain. The advantage of the frequency-domain bases construction approach is that it provides much more flexibility. As a result, the filterbank (basis) can be constructed to fit the features of the signal more closely, and the filter’s frequency response in the filterbank can be designed to be very close t...

G-frames are natural generalizations of frames which cover many other recent generalizations of frames, e.g., bounded quasi-projectors, frames of subspaces, outer frames, oblique frames, pseudo-frames and a class of timefrequency localization operators. Moreover, it was shown that g-frames are equivalent to stable space splittings. In this paper, we study the stability of g-frames. We first pre...

The classical time-frequency distributions represent timeand frequency-localized energy. However, it is not an easy task to analyze multiple signals that have been simultaneously collected. In this paper, a new concept of non-parametric detection and classification of the signals is proposed using the mutual information measures in the time-frequency domain. The time-frequency-based self and mu...

The main objective of this project is to design the full-rate Space-Time-Frequency Trellis code (STFTC), which is based on Quasi-Orthogonal designs for Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems. The proposed Quasi-Orthogonal Space-TimeFrequency Trellis code combines set partitioning and the structure of quasi-orthogonal space-frequency desig...

There is a trend towards flexible radios which are able to cope with a range of wireless communication standards. For the integrated processing of widely different signals — including single-carrier, multicarrier, and spread-spectrum signals — monolithic baseband receivers need universal formats for the signal representation and channel description. We consider a reconfigurable receiver archite...